Near infrared ray shielding film

ABSTRACT

A near infrared screening film which consists of a biaxially oriented film made from a polyester containing a near infrared light absorber having a weight reduction start temperature of at least  280 ° C. and which has a haze value of 5% or less and a total transmittance for visible lights having a wavelength of 400 to 650 nm of 40% or more and which is exemplified by having optical properties at visible and near infrared ranges which satisfy the following expressions (1) to (4):  
     1&lt; T (850)&lt;20  (1)  
     1&lt; T (950)&lt;20  (2)  
     −10&lt; T (620)− T (540)&lt;10  (3)  
     −10&lt; T (450)− T (540)&lt;10  (4)  
     wherein T(450), T(540), T(620), T(850) and T(950) are light transmittances at wavelengths of 450 nm, 540 nm, 620 nm, 850 nm and 950 nm, respectively.  
     This film is inexpensive, has high handling ease, a high visible light transmittance and the function of preventing the malfunction of peripheral equipment caused by near infrared lights from the screen of a plasma display, for example, and can be suitably used in the front panel of the plasma display.

FIELD OF THE INVENTION

[0001] The present invention relates to a near infrared screening filmand a laminated film comprising the same. More specifically, it relatesto a near infrared screening film which is inexpensive, has excellenthandling properties, high visible light transmission and excellentscreening properties for near infrared rays having a wavelength of 820to 980 nm and can be suitably used in the image display panel of aplasma display or the like, and to a laminated film comprising the same.

DESCRIPTION OF THE PRIOR ART

[0002] In the field of visual equipment typified by color TVs, theimplementation of TVs of luminescent panel system using a plasma displayor the like, non-luminescent panel system using a liquid crystal displayor the like and rear projection system using a built-in image projectoris now under way in addition to conventional direct-view TVs using a CRTto meet market demand for a large screen and a high-definition image.

[0003] However, in the plasma displays of luminescent panel system(PDP), rays having a wavelength other than the wavelengths of the threeprimary color (red, green and blue) rays of a color image are radiateddue to the structural factor of each pixel portion constituting a lightsource or discharge portion. For example, strong radiation is measuredat near infrared ranges having wavelengths around 820 nm, 880 nm and 980nm. It is apprehended that this near infrared radiation may cause aproblem such as the malfunction of peripheral equipment. The wavelengthsof the radiated near infrared rays overlap or agree with the operationwavelengths of near infrared rays used by near infrared communicationequipment such as the remote controllers of TVs, videos and airconditions, portable communication equipment and personal computers.

[0004] JP-A 10-156991 (the term “JP-A” as used herein means an“unexamined published Japanese patent application”) proposes anextraneous light reflection preventing film which has the function ofpreventing the malfunction of peripheral equipment caused by nearinfrared rays and also the reflection of extraneous light and can besuitably used in the front panel of an image display device. In thisextraneous light reflection preventing film, the function of preventingthe malfunction of peripheral equipment caused by near infrared rays isprovided by containing an expensive near infrared light absorber in apressure sensitive adhesive layer. To achieve satisfactory near infraredray absorptivity, the pressure sensitive adhesive layer is made as thickas 40 μm, for example.

[0005] The thickness of the pressure sensitive adhesive layer of adisplay such as a plasma display (PDP) is preferably in the range of 5to 40 μm so as to prevent color nonuniformity caused by thicknessnonuniformity. When the layer is thicker than 40 μm, it does notfunction as a self-adhesive and rather reduces handling properties in aprocessing or assembly step. The thickness of the pressure sensitiveadhesive layer to be applied in the example of the above publication is40 μm which is close to the above upper limit.

[0006] As another means of improving a screening effect, the amount of anear infrared light absorber added is increased. However, this reducesthe bonding force of the pressure sensitive adhesive layer and handlingproperties. When an expensive near infrared light absorber is to becontained in the pressure sensitive adhesive layer, it is dissolved in asolvent and the resulting solution is applied with a roll coater orgravure coater, whereby a great loss is produced by the control of filmthickness and productivity, thereby significantly boosting cost.

[0007] As still another means, a screening layer containing a nearinfrared light absorber is formed separate from a pressure sensitiveadhesive layer. In this method, since a bonding function is not requiredof the screening layer, a problem such as a reduction in adhesion doesnot occur unlike the pressure sensitive adhesive layer but the totalthickness of layers becomes large and it is extremely difficult tocontrol the thickness of each layer.

[0008] In a plasma display (PDP), the amount of heat radiation is largeand the temperature of the front panel is high. To prevent these, JP-A10-188822 proposes a panel filter which serves to prevent themalfunction of peripheral equipment caused by near infrared rays andalso cut off heat radiation and can be suitably used in the front panelof an image display device. As example of this, there is disclosed apanel filter which comprises a metal reflection layer for cutting offheat radiation formed on a transparent polyester base film, atransparent coating layer formed on the metal reflection layer and atransparent pressure sensitive adhesive layer having a thickness of 25μm and containing a near infrared light absorber formed on thistransparent coating layer or the other side of the base film.

[0009] Since the metal reflection layer of this filter cuts off bothheat radiation and near infrared radiation, the thickness of thetransparent pressure sensitive adhesive layer containing a near infraredlight absorber may be small. However, the filter still has disadvantagessuch as increases in film thickness and the number of steps resulted bythe formation of the metal reflection layer, thereby boosting cost.

[0010] Accordingly, a near infrared screening film which eliminates useof the above self-adhesive containing a near infrared light absorber andcoating using a solvent and has a sufficiently large thickness and highfilm thickness accuracy has been desired.

SUMMARY OF THE INVENTION

[0011] It is an object of the present invention to provide a nearinfrared screening film which is inexpensive, has excellent handlingproperties, high visible light transmission and the function ofpreventing the malfunction of peripheral equipment caused by nearinfrared rays radiated from the screen of a plasma display and can besuitably used in the front panel of a plasma display.

[0012] It is another object of the present invention to provide a nearinfrared screening film which is inexpensive, has excellent handlingproperties, high light transmission and the function of preventing themalfunction of peripheral equipment caused by near infrared raysradiated from the screen of a plasma display panel and can be suitablyused in the front panel of a luminescent panel display, particularly aplasma display when it is assembled with an electromagnetic shieldingthin film laminated film and a laminated film comprising the same.

[0013] Other objects and advantages of the present invention will becomeapparent from the following description.

[0014] According to the present invention, firstly, the above objectsand advantages of the present invention are attained by a near infraredscreening film (may be referred to as “first single-layer film of thepresent invention” hereinafter) which consists of (A)a biaxiallyoriented film made from a polyester containing a near infrared lightabsorber having a weight reduction start temperature of at least 280° C.and which has (B) a haze value of 5% or less, (C) a total transmittancefor visible lights having a wavelength of 400 to 650 nm of 40% or moreand (D) optical properties at visible and near infrared ranges whichsatisfy the following expressions (1) to (4):

1<T(850)<20  (1)

1<T(950)<20  (2)

−10<T(620)−T(540)<10  (3)

−10<T(450)−T(540)<10  (4)

[0015] wherein T(450), T(540), T(620), T(850) and T(950) are lighttransmittances (%) at wavelengths of 450 nm, 540 nm, 620 nm, 850 nm and950 nm, respectively.

[0016] According to the present invention, secondly, the above objectsand advantages of the present invention are attained by a near infraredscreening film (may be referred to as “second single-layer film of thepresent invention” hereinafter) which consists of (A) a biaxiallyoriented film made from a polyester containing a near infrared lightabsorber having a weight reduction start temperature of at least 280° C.and which has (B) a haze value of 5% or less, (C) a total transmittancefor visible lights having a wavelength of 400 to 650 nm of 60% or moreand (D) optical properties at visible and near infrared ranges whichsatisfy the following expressions (5), (6), (7) and (8):

5≦T(850)≦57  (7)

20≦T(950)  (8)

0.7≦T(620)/T(540)≦1.3  (5)

0.7≦T(450)/T(540)≦1.3  (6)

[0017] wherein T(450), T(540), T(620), T(850) and T(950) are as definedhereinabove.

[0018] According to the present invention, thirdly, the above objectsand advantages of the present invention are attained by a near infraredscreening laminated film (may be referred to as “laminated film of thepresent invention” hereinafter) which comprises (A′) a biaxiallyoriented film made from a polyester containing a near infrared lightabsorber having a weight reduction start temperature of at least 280° C.and an electromagnetic shielding film formed on at least one side of thebiaxially oriented film and which has (B) a haze value of 5% or less,(C) a total transmittance for visible lights having a wavelength of 400to 650 nm of 40% or more, and (D′) optical properties at visible andnear infrared ranges which satisfy the following expressions (1), (2),(5) and (6): 1 < T(850) < 20 (1) 1 < T(950) < 20 (2) 0.7 ≦ T(620)/T(540)≦ 1.3 (5) 0.7 ≦ T(450)/T(540) ≦ 1.3 (6)

[0019] wherein T(450), T(540), T(620), T(850) and T(950) are as definedhereinabove.

BRIEF DESCRIPTION OF THE DRAWINGS

[0020]FIG. 1 is a diagram showing the transmittance of a near infraredfilm used in Example 2;

[0021]FIG. 2 is a diagram showing the transmittance of a near infraredlaminated film used in Example 6;

[0022]FIG. 3 is a diagram showing the transmittance of a near infraredscreening film obtained in Example 9; and

[0023]FIG. 4 is a diagram showing the transmittance of a near infraredscreening film obtained in Example 11.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] The first and second single-layer films of the present inventionwill be described hereinunder. It should be understood that thefollowing description is common to the first and second single-layerfilms unless otherwise stated.

[0025] Light Transmittance

[0026] A description is first given of the first single-layer film.

[0027] The near infrared screening film of the present invention has thefunction of preventing a problem such as the malfunction of peripheralequipment caused by near infrared rays radiated from a plasma displaywhen it is used in the front panel of the plasma display. To this end,the film contains a near infrared light absorber and has transmittancesfor near infrared rays having wavelengths of 850 nm and 950 nm of 1% to20%. When the transmittances for near infrared rays having wavelengthsof 850 nm and 950 nm are higher than 20%, near infrared rays radiatedfrom the plasma display may not be shielded completely, whereby theperipheral equipment of the plasma display may malfunction. When thetransmittances are lower than 1%, the transmittance of visible lightsalso lowers due to the characteristic properties of the near infraredlight absorber, thereby reducing the brightness of the plasma display.

[0028] The above near infrared screening film has a total transmittancefor visible lights of 40% or more, preferably 40% to 80%. When thistotal transmittance is lower than 40%, a reduction in the brightness ofPDP becomes large with the result of reduced visibility. When the totaltransmittance is higher than 80%, contrast is lowered by an intermediatecolor between the luminescent colors of PDP. Therefore, the lower limitof total transmittance is more preferably 50%, particularly preferably60% and the upper limit thereof is more preferably 70%.

[0029] A film containing a near infrared light absorber often sees colornonuniformity due to the characteristic properties of the near infraredlight absorber. The near infrared screening film of the presentinvention suppresses a difference in hue (chroma) as much as possible.In order to suppress the difference in hue, it is effective that thetransmittances at wavelengths of red, green and blue rays of PDP shouldbe made almost equal to one another. Therefore, the differences in thetransmittance (%) of the film at 450 nm, 540 nm and 620 nm which are thepeak wavelengths of blue, green and red rays, that is, (T(450)−T(540))and (T(620)−T(540)) must be set to a range of −10 to 10%. When thedifferences in transmittance (%) are outside the above range, radiationfrom a CRT is greatly colored, thereby reducing visibility. The upperlimit of the differences in transmittance (%) is preferably 8%, morepreferably 5% and the lower limit thereof is preferably −8%, morepreferably −5%.

[0030] A description is subsequently given of the second single-layerfilm.

[0031] The near infrared screening film of the present inventionconsists of a biaxially oriented polyester film which contains a nearinfrared light absorber and must have a transmittance at a wavelength of850 nm of 0.05 to 0.57. The transmittance at a wavelength of 850 nm ispreferably 0.10 to 0.27. The transmittance at a wavelength of 950 nm is0.2 or more, preferably 0.20 to 0.55. When the transmittance at awavelength of 850 nm is higher than 0.57, it is difficult to achieve atransmittance of 0.20 or less after the film is assembled with anelectromagnetic shielding thin film laminated film with the result ofunsatisfactory near infrared screening ability. When the transmittanceat a wavelength of 850 nm is lower than 0.05 or the transmittance at awavelength of 950 nm is lower than 0.20, a near infrared light absorberis used in an amount more than required, thereby boosting cost.Therefore, there will be no advantage from assembling the film with anelectromagnetic shielding thin film laminated film.

[0032] The near infrared screening film of the present invention musthave a haze value of 5% or less and optical properties at a visiblerange which satisfy the following expressions (5) and (6):

0.7≦T(620)/T(540)≦1.3  (5)

0.7≦T(450)/T(540)≦1.3  (6)

[0033] wherein T(450), T(540) and T(620) are transmittances atwavelengths of 450 nm, 540 nm and 620 nm, respectively.

[0034] This haze value is preferably 3% or less, particularly preferably2% or less. When this haze value is larger than 5%, the obtained imagebecomes unclear with a clouded color, thereby reducing visibility. SinceR, G and B rays radiated from a plasma display have wavelengths around620 nm, 540 nm and 450 nin, respectively, when T(620)/T(540) andT(450)/T(540) is 0.7 or less or 1.3 or more, the balance among thebrightness's of R, G and B rays is lost, thereby making it impossible todisplay colors properly. Further, the total transmittance for visiblerays (wavelength of 400 to 650 nm) is 60% or more, preferably 70% ormore. When the total transmittance is lower than 60%, the entire imagebecomes dark and power consumption for achieving sufficient brightnessbecomes larger than required.

[0035] Near Infrared Light Absorber

[0036] In the present invention, when a near infrared light absorber iscontained in the film to increase the absorbance of an infraredwavelength range of the film, it is important that the haze value of thefilm should not be made large and the haze value of the biaxiallyoriented film must be set to 5% or less. The content of the nearinfrared light absorber is preferably 0.10 to 1.00 g/m² of the planeperpendicular to the thickness direction of the biaxially orientedpolyester film. When this haze value is larger than 5%, the obtainedimage becomes unclear with a clouded color, thereby reducing visibility.As means of maintaining the haze value of the biaxially oriented film at5% or less and adjusting the transmittances at 850 nm and 950 nm to 20%or less, the near infrared light absorber is preferably dissolved in apolyester which will become a base film or made a dispersant having aparticle diameter of 500 nm or less. The haze value of the biaxiallyoriented film is preferably 3% or less, particularly preferably 2% orless.

[0037] In general, near infrared light absorbers have lower thermalstability than that of inorganic pigments. The near infrared lightabsorber in the present invention must not deteriorate or decomposewhile it is dissolved in a polyester, or even if it deteriorates ordecomposes, its deterioration or decomposition must be small. Morespecifically, the weight reduction start temperature of the nearinfrared light absorber must be at least 280° C. Further; the weightreduction rate is preferably 10% or less when the near infrared lightabsorber is kept at 280° C. for 30 minutes from the viewpoints of therecovery and recycling of a polyester film, particularly a polyethyleneterephthalate (PET) film. When the weight reduction rate is 10% or less,a portion which does not become a film product of the polymer can berecovered and used as a film forming raw material again. When the weightreduction rate is larger than 10%, the deterioration or decomposition ofthe near infrared light absorber proceeds at the time of recovering thefilm and it is difficult to maintain substantially the same opticalproperties as a virgin polymer. Further, a near infrared light absorberwhich rarely reduces the melt viscosity of the polyester at the time ofmelt extruding the polyester is preferably used from the viewpoint offilm productivity.

[0038] The near infrared light absorber having the above heat resistanceis preferably a compound having a phthalocyanine skeleton or a nickelcomplex compound. Examples of the near infrared light absorber includethe EX812K, EX814K and EX906B near infrared light absorbers of NipponShokubai Co., Ltd., the R12 and S13 near infrared light absorbers ofMitsui Chemical, Inc., the IR-ADDITIVE200 near infrared light absorberof Dainippon Ink and Chemicals, Inc., the SDO-1000B near infrared lightabsorber of Arimoto Kagaku Co., Ltd. and the IRG-023 near infrared lightabsorber of Nippon Kayaku Co., Ltd. They may be used alone butpreferably used in combination of two or more.

[0039] Although the near infrared light absorber has poorweatherability, the polyester which will become a base film in thepresent invention absorbs most of ultraviolet rays unlike an acrylicbase film, thereby making it possible to use a near infrared lightabsorber without worrying about weatherability. An ultraviolet lightabsorber may be optionally added to the polyester to further improveweatherability.

[0040] Addition Method

[0041] As for the method of adding the above near infrared lightabsorber, a predetermined amount of the near infrared light absorber maybe dispersed or dissolved in the same glycol as a glycol component ofthe polyester, such as ethylene glycol, and may be added in theproduction stage of the polyester. It is preferred from the viewpointsof film productivity, the prevention of inclusion of foreign matter andthe simplification of the step that a polyester pellet (master pellet)having a higher content of a near infrared light absorber than itscontent of the film or a pellet produced by melting and solidifying anear infrared light absorber itself be prepared and added in the filmproduction step. A suitable binder may be used to melt and solidify thenear infrared light absorber. As for the addition method, the pelletproduced by melting and solidifying a near infrared light absorber ispreferably supplied to a film forming step using a small-sized feeder,particularly the extruder of the polyester pellet as the above pelletdiffers from the polyester pellet which is a film raw material inmechanical properties. The supply by the feeder which is changed by thecapacity of the extruder and the amount of addition is preferably 0.2 to20 kg/h in consideration of the equipment. In order to suppress areduction in the viscosity of the molten polyester, the residence timeis preferably 20 to 4,000 seconds at a shear deformation rate of theextruder of 70 (1/sec). When this value is smaller than 20 seconds, thekneading of the near infrared light absorber is not enough and the filmbecomes nonuniform in transmittance and when the value is larger than4,000 seconds, the film is easily broken and the near infrared lightabsorber is readily thermally decomposed by a reduction in the viscosityof the molten polyester.

[0042] As the near infrared screening film of the present invention canreduce the amount of the near infrared light absorber compared with thecase where the near infrared light absorber is contained in a coatinglayer such as a pressure sensitive adhesive layer, color nonuniformityis hardly seen on the plane of the film and a color change caused by ableed-out of the near infrared light absorber hardly occurs.

[0043] Polyester

[0044] The polyester for forming the biaxially oriented film of thepresent invention is a linear saturated polyester synthesized from anaromatic dibasic acid or an ester forming derivative thereof (forexample, a lower alkyl ester) and a diol or an ester forming derivativethereof (for example, a lower fatty acid ester, cyclic ether, etc.).Examples of the polyester include polyethylene terephthalate,polyethylene isophthalate, polypropylene terephthalate, polybutyleneterephthalate, poly(1,4-cyclohexylene dimethylene terephthalate) andpolyethylene-2,6-naphthalene dicarboxylate. Copolymers and blendsthereof are also included. Out of these, what comprise 70 wt % or moreof ethylene terephthalate or ethylene-2,6-naphthalene dicarboxylatebased on the weight of the polyester are preferred, and polyethyleneterephthalate comprising ethylene terephthalate as the main recurringunit is particularly preferred from the viewpoints of the workabilityand transparency of the biaxially oriented film.

[0045] As the comonomer of the above polyethylene terephthalate,dicarboxylic acid components include aromatic dicarboxylic acids such asisophthalic acid, phthalic acid and 2,6-naphthalenedicarboxylic acid;aliphatic dicarboxylic acids such as adipic acid, azelaic acid, sebacicacid and decanedicarboxylic acid; and alicyclic dicarboxylic acids suchas cyclohexanedicarboxylic acid. Diol components include aliphatic diolssuch as 1,4-butanediol, 1,6-hexanediol and diethylene glycol; alicyclicdiols such as 1,4-cyclohexanedimethanol; and aromatic diols such asbisphenol A. These comonomers may be used alone or in combination of twoor more. Out of these comonomers, isophthalic acid is particularlypreferred from the viewpoints of workability and transparency.

[0046] The amount of the comonomer which changes according to its typeis preferably such that the melting point of the polymer does not becomelower than 230° C., preferably lower than 240° C. When the melting pointof the polymer is lower than 230° C., the polymer may deteriorate inheat resistance and mechanical strength. When the copolyester comprisesethylene terephthalate as the main recurring unit and isophthalic acidas a comonomer, it contains isophthalic acid in an amount of 12 mol % orless based on the total number of moles of all the acid components. Themelting point of the polyester is measured by a method for obtaining amelting peak with the 910DSC of DuPont Instruments Co., Ltd. at atemperature elevation rate of 20° C./min. The amount of a sample is 20mg.

[0047] The above polyester can be produced by a method known per se.Preferred examples of the method include one in which terephthalic acidand ethylene glycol and optionally a comonomer (for example, isophthalicacid) are esterified and the obtained reaction product is polycondenseduntil a targeted polymerization degree is achieved to produce apolyester, and one which terephthalic acid dimethyl ester and ethyleneglycol and optionally a comonomer (for example, isophthalic aciddimethyl ester) are subjected to an ester exchange reaction and theobtained reaction product is polycondensed until a targetedpolymerization degree is achieved to produce a polyester. As a matter ofcourse, 2,6-naphthalenedicarboxylic acid may be used as the main acidcomponent and 1,4-cyclohexanedimethanol may be used as the main glycolcomponent. The polyester obtained by the above method (meltpolymerization) can have a higher degree of polymerization by apolymerization method in a solid-phase state (solid-phasepolymerization) as required.

[0048] An unstretched film is produced from the thus obtained polyesterby a molten film forming method known per se, that is, by melting thepolyester and extruding it from a linear die, stretched in biaxialdirections and heat set to produce a biaxially oriented film. Ingeneral, the stretching temperature is (Tg (glass transition temperatureof a polyester)−10) to (Tg+70)° C. and the draw ratio is 2.5 to 8 timesin each direction. Preferably, the heat setting temperature is 180 to250° C. and the heat setting time is 1 to 60 seconds.

[0049] The intrinsic viscosity (orthochlorophenol, 35° C.) of thepolyester for forming the above biaxially oriented film is preferably0.45 to 1.50, more preferably 0.48 to 1.00, particularly preferably 0.50to 0.80. When the intrinsic viscosity is lower than 0.45, film formingproperties may become inferior disadvantageously. When the intrinsicviscosity is higher than 1.50, moldability may be impaired, an overloadmay be imposed on the extruder, or the intrinsic viscosity may begreatly reduced by an overrise in the resin temperature.

[0050] In the present invention, additives such as an antioxidant,thermal stabilizer, viscosity modifier, plasticizer, color improvingagent, lubricant, nucleating agent, ultraviolet light absorber,antistatic agent, antioxidant and catalyst may be added optionally inthe polyester production step or the subsequent step before extrusionfrom a die.

[0051] In the present invention, a substance (filler; lubricant) forroughening the surface of the film is preferably contained in thepolyester to improve the traveling properties and slipperiness of thebiaxially oriented film. Fillers known as a slipperiness providing agentfor a polyester film are used as the filler. Illustrative example of thefiller include calcium carbonate, calcium oxide, aluminum oxide, kaolin,silicon oxide, zinc oxide, carbon black, silicon carbide, tin oxide,crosslinked acrylic resin particles, crosslinked polystyrene resinparticles, melamine resin particles and crosslinked silicone resinparticles. Out of these, porous silica is preferred because it easilyprovides slipperiness while retaining transparency. The average particlediameter of the filler is preferably 1 to 3 μm, more preferably 1.2 to2.4 μm. The amount of the filler is preferably 0.01 to 0.005 wt %, morepreferably 0.008 to 0.006 wt % from the viewpoints of the transparencyand slipperiness of the film.

[0052] In the present invention, the effect of the near infrared lightabsorber can be maximized by containing an ultraviolet light absorber inthe biaxially oriented film. That is, since a conventional near infraredscreening film has the coating layer of a near infrared light absorberon the coating layer of an ultraviolet light absorber, its near infraredscreening ability is reduced by the mixing and reaction of the bothabsorbers. However, as the biaxially oriented film is much thicker thanthe coating layers, when the ultraviolet light absorber is contained inthe biaxially oriented film, the mixing and reaction of the bothabsorbers can be prevented. Therefore, in the present invention, anultraviolet light absorber which can be contained in a biaxiallyoriented film is preferred, and an ultraviolet light absorber whichhardly reacts with a near infrared light absorber is more preferred. Anultraviolet light absorber which has both of the above features will bedescribed in more detail.

[0053] The above ultraviolet light absorber is preferably at least onecyclic imino ester in an unreacted form selected from the groupconsisting of a compound represented by the following formula (I):

[0054] wherein X¹ is a divalent aromatic residue having two bonds at the1-position and 2-position, n is 1, 2 or 3, and R¹ is a hydrocarbonresidue having a valence of n which may further contain a hetero atom ormay be a direct bond when n is 2, and a compound represented by thefollowing formula (II):

[0055] wherein A is a group represented by the following formula (II)-a:

[0056] or the following formula (II)-b:

[0057] R² and R³ are the same or different and each a monovalenthydrocarbon residue, and X² is a quadrivalent aromatic residue which maycontain a hetero atom.

[0058] The cyclic imino ester is a known compound as an ultravioletlight absorber as disclosed in JP-A 59-12952.

[0059] Examples of the cyclic imino ester represented by the aboveformulas (I) and (II) are given below.

[0060] Compounds of the Above Formula (I)

[0061] When n is 1

[0062] 2-methyl-3,1-benzooxazin-4-one,

[0063] 2-butyl-3,1-benzooxazin-4-one,

[0064] 2-phenyl-3,1-benzooxazin-4-one, 2-(1- or2-naphthyl)-3,1-benzooxazin-4-one,

[0065] 2-(4-biphenyl)-3,1-benzooxazin-4-one,

[0066] 2-p-nitrophenyl-3,1-benzooxazin-4-one,

[0067] 2-m-nitrophenyl-3,1-benzooxazin-4-one,

[0068] 2-p-benzoylphenyl-3,1-benzooxazin-4-one,

[0069] 2-p-methoxyphenyl-3,1-benzooxazin-4-one,

[0070] 2-o-methoxyphenyl-3,1-benzooxazin-4-one,

[0071] 2-cyclohexyl-3,1-benzooxazin-4-one, 2-p-(orm-)phthalimidophenyl-3,1-benzooxazin-4-one,

[0072] N-phenyl-4-(3,1-benzooxazin-4-on-2-yl)phthalimide,

[0073] N-benzoyl-4-(3,1-benzooxazin-4-on-2-yl)aniline,

[0074] N-benzoyl-N-methyl-4-(3,1-benzooxazin-4-on-2-yl)aniline,

[0075] 2-(p-(N-methylcarbonyl)phenyl)-3,1-benzooxazin-4-one

[0076] When n is 2

[0077] 2,2′-bis(3,1-benzooxazin-4-one),

[0078] 2,2′-ethylenebis(3,1-benzooxazin-4-one),

[0079] 2,2′-tetramethylenebis(3,1-benzooxazin-4-one),

[0080] 2,2′-decamethylenebis(3,1-benzooxazin-4-one),

[0081] 2,2′-p-phenylenebis(3,1-benzooxazin-4-one),

[0082] 2,2′-m-phenylenebis(3,1-benzooxazin-4-one),

[0083] 2,2′-(4,4′-diphenylene)bis(3,1-benzooxazin-4-one),

[0084] 2,2′-(2,6- or 1,5-naphthylene)bis(3,1-benzooxazin-4-one),

[0085] 2,2′-(2-methyl-p-phenylene)bis(3,1-benzooxazin-4-one),

[0086] 2,2′-(2-nitro-p-phenylene)bis(3,1-benzooxazin-4-one),

[0087] 2,2′-(2-chloro-p-phenylene)bis(3,1-benzooxazin-4-one),

[0088] 2,2′-(1,4-cyclohexylene)bis(3,1-benzooxazin-4-one),

[0089] N-p-(3,1-benzooxazin-4-on-2-yl)phenyl,

[0090] 4-(3,1-benzooxazin-4-on-2-yl)phthalimide,

[0091] N-p-(3,1-benzooxazin-4-on-2-yl)benzoyl,

[0092] 4-(3,1-benzooxazin-4-on-2-yl)aniline

[0093] When n is 3

[0094] 1,3,5-tri(3,1-benzooxazin-4-on-2-yl)benzene,

[0095] 1,3,5-tri(3,1-benzooxazin-4-on-2-yl)naphthalene,

[0096] 2,4,6-tri(3,1-benzooxazin-4-on-2-yl)naphthalene

[0097] Compounds of the Above Formula (II)

[0098] 2,8-dimethyl-4H,6H-benzo(1,2-d;5,4-d′)bis(1,3)-oxazin-4, 6-dione,

[0099] 2,7-dimethyl-4H,9H-benzo(1,2-d;4,5-d′)bis(1,3)oxazin-4,9-dione,

[0100] 2,8-diphenyl-4H,8H-benzo(1,2-d;5,4-d′)bis(1,3)-oxazin-4, 6-dione,

[0101] 2,7-diphenyl-4H,9H-benzo(1,2-d;4,5-d′)bis(1,3)-oxazin-4, 6-dione,6,6′-bis(2-methyl-4H,3,1-benzooxazin-4-one),

[0102] 6,6′-bis(2-ethyl-4H,3,1-benzooxazin-4-one),

[0103] 6,6′-bis(2-phenyl-4H,3,1-benzooxazin-4-one),

[0104] 6,6′-methylenebis(2-methyl-4H,3,1-benzooxazin-4-one),

[0105] 6,6′-methylenebis(2-phenyl-4H,3,1-benzooxazin-4-one),

[0106] 6,6′-ethylenebis(2-methyl-4H,3,1-benzooxazin-4-one),

[0107] 6,6′-ethylenebis(2-phenyl-4H,3,1-benzooxazin-4-one),

[0108] 6,6′-butylenebis(2-methyl-4H,3,1-benzooxazin-4-one),

[0109] 6,6′-butylenebis(2-phenyl-4H,3,1-benzooxazin-4-one),

[0110] 6,6′-oxybis(2-methyl-4H,3,1-benzooxazin-4-one),

[0111] 6,6′-oxybis(2-phenyl-4H,3,1-benzooxazin-4-one),

[0112] 6,6′-sulfonylbis(2-methyl-4H,3,1-benzooxazin-4-one),

[0113] 6,6′-sulfonylbis(2-phenyl-4H,3,1-benzooxazin-4-one),

[0114] 6,6′-carbonylbis(2-methyl-4H,3,1-benzooxazin-4-one),

[0115] 6,6′-carbonylbis(2-phenyl-4H,3,1-benzooxazin-4-one),

[0116] 7,7′-methylenebis(2-methyl-4H,3,1-benzooxazin-4-one),

[0117] 7,7′-methylenebis(2-phenyl-4H,3,1-benzooxazin-4-one),

[0118] 7,7′-bis(2-methyl-4H,3,1-benzooxazin-4-one),

[0119] 7,7′-ethylenebis(2-methyl-4H,3,1-benzooxazin-4-one),

[0120] 7,7′-oxybis(2-methyl-4H,3,1-benzooxazin-4-one),

[0121] 7,7′-sulfonylbis(2-methyl-4H,3,1-benzooxazin-4-one),

[0122] 7,7′-carbonylbis(2-methyl-4H,3,1-benzooxazin-4-one),

[0123] 6,7′-bis(2-methyl-4H,3,1-benzooxazin-4-one),

[0124] 6,7′-bis(2-phenyl-4H,3,1-benzooxazin-4-one),

[0125] 6,7′-methylenebis(2-methyl-4H,3,1-benzooxazin-4-one),

[0126] 6,7′-methylenebis(2-phenyl-4H,3,1-benzooxazin-4-one)

[0127] Out of the above compounds, compounds of the above formula (I)are preferred, compounds of the above formula (I) in which n is 2 aremore preferred, and compounds represented by the following formula (I)-1are particularly preferred:

[0128] wherein R¹¹ is a divalent aromatic hydrocarbon residue.

[0129] Out of the compounds represented by the above formula(I)-1,2,2′-p-phenylenebis(3,1-benzooxazin-4-one),2,2′-(4,4′-diphenylene)bis(3,1-benzooxazin-4-one) and2,2′-(2,6-naphthylene)bis(3,1-benzooxazin-4-one) are preferred.

[0130] The amount of the above ultraviolet light absorber is preferably0.1 to 5 wt %, more preferably 0.2 to 3 wt % based on the polyester.When the amount is smaller than 0.1 wt %, the effect of preventingdeterioration by ultraviolet rays is small and when the amount is largerthan 5 wt %, the film forming properties of the polyester deterioratedisadvantageously. The ultraviolet light absorber is preferably addedduring the polymerization or melt extrusion of the polyester. At thispoint, the ultraviolet light absorber can be formed as a master pelletand then be added, which is preferred.

[0131] The thickness of the biaxially oriented film of the presentinvention is preferably 50 μm or more because it can suppress thescattering of glass when PDP is broken. The upper limit of thickness ofthe biaxially oriented film is preferably 250 μm from the viewpoints ofease of maintaining the haze value at 5% or less and film productivity.

[0132] Adhesive Layer

[0133] The biaxially oriented polyester film of the present inventionpreferably comprises an adhesive layer formed on at least one sidethereof to improve adhesion to a hard coat layer and a pressuresensitive adhesive layer which will be described hereinafter andworkability. This adhesive layer can be formed by applying an aqueouscoating fluid which comprises a polyester resin, acrylic resin ormixture thereof and wax to the biaxially oriented polyester film anddrying it during the production process of the biaxially oriented film.

[0134] The above aqueous polyester resin is, for example, an aqueouspolyester resin which comprises the following polybasic acid componentand polyol component. Examples of the polybasic acid component includeterephthalic acid, isophthailc acid, phthalic acid, phthalic anhydride,2,6-naphthalenedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid,adipic acid, sebacic acid, trimellitic acid, pyromellitic acid, dimericacid and 5-sodiumsulfoisophthalic acid. A copolyester resin ispreferably synthesized from two or more of the above acid components. Atrace amount of a hydroxycarboxylic acid such as maleic acid, itaconicacid or p-hydroxybenzoic acid as an unsaturated polybasic acid componentmay also be used. Examples of the polyol component include ethyleneglycol, 1,4-butanediol, diethylene glycol, dipropylene glycol,1,6-hexanediol, 1,4-cyclohexanedimethanol, xylene glycol,dimethylolpropane, poly(ethylene oxide)glycol and poly(tetramethyleneoxide)glycol. The present is not limited to these monomers.

[0135] The aqueous polyester resin can be produced from a polybasic acidor ester forming derivative thereof (for example, dimethyl ester, acidanhydride, etc.) and a polyol or ester forming derivative thereof (forexample, lower fatty acid ester, cyclic anhydride, etc.) by aconventionally known polymerization method.

[0136] The above aqueous acrylic resin can be obtained by copolymerizingthe following acrylic monomer. Examples of the acrylic monomer includealkyl acrylates and alkyl methacrylates (examples of the alkyl groupinclude methyl group, ethyl group, n-propyl group, isopropyl group,n-butyl group, isobutyl group, t-butyl group, 2-ethylhexyl group andcyclohexyl group); hydroxy group-containing monomers such as2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropylacrylate and 2-hydroxypropyl methacrylate; epoxy group-containingmonomers such as glycidyl acrylate, glycidyl methacrylate and allylglycidyl ether; monomers containing a carboxy group or a salt thereofsuch as acrylic acid, methacrylic acid, itaconic acid, maleic acid,fumaric acid, crotonic acid, styrenesulfonic acid and salts thereof(sodium salts, potassium salts, ammonium salts, tertiary amine salts,etc.); monomers containing an amido group such as acrylamide,methacrylamide, N-alkylacrylamide, N-alkylmethacrylamide,N,N-dialkylacrylamide, N,N-dialkylmethacrylates (examples of the alkylgroup include methyl group, ethyl group, n-propyl group, isopropylgroup, n-butyl group, isobutyl group, t-butyl group, 2-ethylhexyl groupand cyclohexyl group), N-alkoxyacrylamide, N-alkoxymethacrylamide,N,N-dialkoxyacrylamide, N,N-dialkoxymethacrylamide (examples of thealkoxy group include methoxy group, ethoxy group, butoxy group andisobutoxy group), acryloylmorpholine, N-methylolacrylamide,N-methylolmethacrylamide, N-phenylacrylamide and N-phenylmethacrylamide;acid anhydride monomers such as maleic anhydride and itaconic anhydride;and other monomers such as vinyl isocyanate, allyl isocyanate, styrene,α-methylstyrene, vinylmethyl ether, vinylethyl ether,vinyltrialkoxysilane, alkylmaleic acid monoester, alkylfumaric acidmonoester, alkylitaconic acid monoester, acrylonitrile,methacrylonitrile, vinylidene chloride, ethylene, propylene, vinylchloride, vinyl acetate and butadiene. The present invention is notlimited to these monomers.

[0137] Examples of the above wax include vegetable waxes such ascarnauba wax, candelilla wax, rice wax, haze wax, Jojoba oil, palm wax,rosin-modified wax, urucury wax, cane wax, esparto wax and bark wax,animal waxes such as beeswax, lanoline, whale wax, insect wax andshellac wax, mineral waxes such as montan wax, ozokerite and ceresinewax, petroleum waxes such as paraffin wax, micro-crystalline wax andpetrolactam, and synthetic hydrocarbon-based waxes such asFischer-Tropsch, polyethylene wax, polyethylene oxide wax, polypropylenewax and polypropylene oxide wax. Out of these, carnauba wax, paraffinwax and polyethylene wax are preferred because they have excellentadhesion to a hard coat and a self-adhesive and high lubricity. Further,a water dispersion thereof is more preferred from the viewpoints of anenvironmental problem and handling ease.

[0138] The polyester resin for forming a coating layer is contained inthe coating layer in an amount of preferably 50 to 95 wt %, morepreferably 60 to 90 wt %. Another resin for forming the coating layer(for example, an acrylic resin) is contained in the coating layer in anamount of preferably 5 to 30 wt %, more preferably 10 to 25 wt %. Whenthe amount of the polyester resin is larger than 95 wt % or the amountof the acrylic resin is smaller than 5 wt %, adhesion may becomeunsatisfactory. When the amount of the acrylic resin is larger than 30wt %, the transparency of the coating layer may lower because theacrylic resin is not compatible with the polyester resin. Wax ispreferably contained in the coating layer in an amount of 0.5 to 20 wt%. The amount is more preferably 1 to 10 wt %. When the amount of thewax is smaller than 0.5 wt %, the lubricity of the surface of the filmmay not be obtained. When the amount is larger than 20 wt %, closeadhesion to a polyester base film or adhesion to a hard coat and aself-adhesive may become unsatisfactory.

[0139] The above composition is preferably used in the form of anaqueous coating fluid such as an aqueous solution, water dispersion oremulsion to form a coating film. To form the coating film, resins otherthan the above composition, such as a polymer having an oxazoline group,crosslinking agent such as melamine, epoxy or aziridine, antistaticagent, colorant, surfactant, ultraviolet light absorber and lubricant(filler) may be optionally added. Particularly, lubricity and antiblockproperties can be further improved by adding a lubricant.

[0140] The solids content of the aqueous coating fluid is preferably 20wt % or less, more preferably 1 to 10 wt %. When the content is lowerthan 1 wt %, coatability on the polyester film becomes unsatisfactoryand when the content is higher than 20 wt %, the stability of thecoating agent and the appearance of a coat may deteriorate.

[0141] The aqueous coating fluid may be applied to the polyester film inany stage but preferably in the production step of the polyester film,more preferably to the polyester film before the orientation of crystalsis completed.

[0142] The polyester film before the orientation of crystals iscompleted is an unstretched film, a monoaxially stretched film obtainedby stretching an unstretched film in a longitudinal or transversedirection or a biaxially oriented film obtained by stretching anunstretched film in both longitudinal and transverse directions at a lowdraw ratio (or a biaxially oriented film obtained by stretching thebiaxially oriented film in a longitudinal or transverse direction againbefore the orientation of crystals is completed).

[0143] Preferably, the aqueous coating fluid of the above composition isapplied to the unstretched film or monoaxially stretched film and thenthe film is stretched in a longitudinal direction and/or transversedirection and heat set.

[0144] In order to apply the coating fluid to the film, preferably, thesurface of the film is subjected to a physical pre-treatment such as acorona surface treatment, flame treatment or plasma treatment, or thecomposition is used in combination with a surfactant which is chemicallyinactive with the composition to improve coatability.

[0145] Examples of the surfactant which improves the wettability of thepolyester film by the aqueous coating fluid include anionic and nonionicsurfactants such as polyoxyethylene alkylphenyl ethers,polyoxyethylene-fatty acid esters, sorbitan fatty acid esters, glycerinfatty acid esters, fatty acid metal soap, alkylsulfuric acid salts,alkylsulfonic acid salts and alkylsulfosuccinic acid salts. Thesurfactant is preferably contained in the composition for forming acoating film in an amount of 1 to 10 wt %.

[0146] The coating weight of the coating fluid is such that thethickness of the coating film becomes preferably 0.02 to 0.3 μm, morepreferably 0.07 to 0.25 μm. When the thickness of the coating film istoo small, adhesive force becomes unsatisfactory and when the thicknessis too large, blocking may occur or the haze value may become large.

[0147] Known coating techniques may be used. For example, roll coating,gravure coating, roll brushing, spray coating, air knife coating,impregnation and curtain coating may be used alone or in combination.The coating film may be formed on only one side or both sides of thefilm.

[0148] Hard Coat Layer

[0149] A near infrared screening film laminate can be produced byforming the above adhesive layer on both sides of the near infraredscreening film of the present invention, a hard coat layer on one of theadhesive layers and a second adhesive layer on the other adhesive layer.

[0150] The material of the above hard coat layer is not limited to aparticular resin if it becomes hard enough to stand practical use, asexemplified by ionizing radiation curable resins, thermosetting resinsand thermoplastic resins. It is preferably an ionizing radiation curableresin which facilitates the work of forming a film on a base film andeasily increases its pencil hardness to a desired value.

[0151] The ionizing radiation curable resin used to form the hard coatlayer is preferably a resin having an acrylate-based functional group,particularly preferably a polyester acrylate or urethane acrylate. Theabove polyester acrylate is an acrylate and/or methacrylate of anoligomer of a polyester-based polyol (the acrylate and methacrylate willbe generally referred to as “(meth)acrylate” hereinafter). The aboveurethane acrylate is an acrylate of an oligomer of a polyol compound anda diisocyanate compound. The monomer for forming the acrylate isselected from methyl (meth)acrylate, ethyl (meth)acrylate, butyl(meth)acrylate, 2-ethylhexyl(meth)acrylate, methoxyethyl (meth)acrylate,butoxyethyl (meth)acrylate and phenyl (meth)acrylate.

[0152] To further enhance the hardness of the hard coat layer, apolyfunctional monomer is preferably used. Preferred examples of thepolyfunctional monomer include trimethylolpropane tri(meth)acrylate,hexanediol (meth)acrylate, tripropylene glycol di(meth)acrylate,diethylene glycol di(meth)acrylate, pentaerythritol tri(meth)acrylate,dipentaerythritol hexa(meth)acrylate, 1,6-hexanediol di(meth)acrylateand neopentyl glycol di(meth)acrylate.

[0153] Examples of the polyester-based oligomer used to form the hardcoat layer include condensates of adipic acid or sebacic acid as an acidcomponent and a glycol (for example, ethylene glycol, polyethyleneglycol, propylene glycol, butylene glycol, polybutylene glycol, etc.) ortriol (for example, glycerin, trimethylolpropane, etc.), and condensatesobtained by condensing a triol component with these, such as polyadipatetriol and poly(polyolsebacate). Part or all of the above aliphaticdicarboxylic acid may be substituted by another organic acid. In thiscase, the another organic acid is preferably isophthalic acid,terephthalic acid or phthalic anhydride because it provides highhardness to the hard coat layer.

[0154] The polyurethane-based oligomer used to form the hard coat layeris obtained from a condensate of a polyisocyanate and a polyol. Examplesof the polyisocyanate include methylene•bis(p-phenylenediisocyanate),hexamethylene diisocyanate•hexanetriol adduct, hexamethylenediisocyanate, tolylene diisocyanate, tolylenediisocyanate•trimethylolpropane adduct, 1,5-naphthylene diisocyanate,thiopropyl diisocyanate, ethylbenzene-2,4-diisocyanate, 2,4-tolylenediisocyanate dimmer, hydrogenated xylylene diisocyanate andtris(4-phenylisocyanate)thiophosphate. Examples of the polyol includepolyether-based polyols such as polyoxytetramethylene glycol,polyester-based polyols such as polyadipate polyol and polycarbonatepolyol, and copolymers of an acrylic acid ester and hydroxyethylmethacrylate.

[0155] Further, when an ultraviolet curable resin is used as the aboveionizing radiation curable resin, a photopolymerization initiator suchas an acetophenone, benzophenone, Michler benzoyl benzoate, α-amyloximeester or thioxanthone and an optical sensitizer such as n-butylamine,triethylamine or tri-n-butylphosphine are preferably mixed into theresin.

[0156] The above urethane acrylate has high elasticity and flexibilityand excellent workability (folding endurance) but its surface hardnesstends to be unsatisfactory, thereby making it difficult to obtain apencil hardness of 2H or more. In contrast to this, a polyester acrylatemakes it possible to form a hard coat layer having extremely highhardness by selecting the constituent components of a polyester. Then, ahard coat layer comprising 60 to 90 parts by weight of an urethaneacrylate and 40 to 10 parts by weight of a polyester acrylate ispreferred because it has both high hardness and flexibility.

[0157] The coating fluid used to form the hard coat layer preferablycontains inert fine particles having a secondary particle diameter of 20μm or less in an amount of 0.3 to 3 parts by weight based on 100 partsby weight of the resin component to adjust gloss and provide surfaceslipperiness (not releasability). When the amount of the fine particlesis smaller than 0.3 part by weight, the effect of improving slipperinessbecomes unsatisfactory and when the amount is larger than 3 parts byweight, the pencil hardness of the obtained hard coat layer may lower.Preferred examples of the inert fine particles to be added to thecoating fluid include inorganic fine particles such as silica, magnesiumcarbonate, aluminum hydroxide and barium sulfate, and organic polymerfine particles such as polycarbonate, acrylic resin, polyimide,polyamide, polyethylene naphthalate and melamine resin.

[0158] The coating technique for forming the hard coat layer is suitablyselected from conventional techniques known per se according to thecharacteristic properties and coating weight of the coating fluid, suchas roll coating, gravure coating, bar coating and extrusion coating. Thethickness of the hard coat layer is not particularly limited butpreferably 1 to 15 μm.

[0159] Antireflection Layer

[0160] The antireflection layer of the near infrared screening filmlaminate of the present invention is formed on the surface of the hardcoat layer. Preferably, it is a laminate formed by alternatelylaminating together a plurality of layers having different refractiveindices and its structure is generally known. Examples of the laminateinclude a laminate consisting of two antireflection layers formed bysol-gel wet coating, a laminate consisting of three antireflectionlayers formed by sputtering and a combination thereof formed to achievehigh cost efficiency and performance.

[0161] The above antireflection layer is not particularly limited if itdoes not impair the above optical properties of the near infraredscreening film laminate. Examples of the antireflection layer include(1) an antireflection layer composed of an MgF₂ extremely thin filmhaving a thickness of about 0.1 μm, (2) an antireflection layer composedof a metal deposited film, (3) an antireflection layer made from amaterial having a lower refractive index than that of the hard coatlayer and formed on the hard coat layer, (4) an antireflection layerlaminate consisting of a high refractive index layer formed on the hardcoat layer and a low refractive index layer having a lower refractiveindex than the high refractive index layer formed on the high refractiveindex layer (for example, a layer of super fine particles of a metaloxide having a high refractive index formed in a portion in contact withthe hard coat layer of the antireflection layer), (5) an antireflectionlayer laminate formed by alternately laminating together a plurality ofthe antireflection layers (4) and (6) an antireflection layer laminateconsisting of a high refractive index layer, an intermediate refractiveindex layer having a lower refractive index than the high refractiveindex layer on the inner side (on the screen side when the film isassembled with the screen) of the high refractive index layer and a lowrefractive index layer having a lower refractive index than theintermediate refractive index layer on the outer side (side opposite tothe screen side when the film is assembled with the screen) of the highrefractive index layer.

[0162] Out of these, an antireflection layer laminate consisting of anintermediate refractive index layer, a high refractive index layer and alow refractive index layer formed on the hard coat layer on the basefilm 1 in the mentioned order is preferred because it can preventreflection more effectively. An antireflection layer laminate consistingof a low refractive index layer having a refractive index of more than1.4 and a thickness of 80 to 110 nm, an intermediate refractive indexlayer having a thickness of 50 to 100 nm and a high refractive indexlayer having a refractive index of less than 2.2 and a thickness of 30to 110 nm, all of which are made from SiOx and have an optical thicknessD (D=n·d, n; refractive index of the intermediate refractive indexlayer, d: thickness of the intermediate refractive index layer) smallerthan the wavelength of visible light is more preferred.

[0163] The above antireflection layer of the near infrared screeningfilm laminate of the present invention can suppress the reflection ofextraneous light which impairs the visibility of a display. There isalso available an antireflection single layer which prevents thereflection of a yellow ray mainly. However, an antireflectionmulti-layer film is suitable for the prevention of reflection of adisplay.

[0164] Second Adhesive Layer

[0165] The near infrared screening film laminate of the presentinvention has a second adhesive layer on the side opposite to the hardcoat layer side. When the second adhesive layer is to be laminated withthe biaxially oriented film, it is preferred to laminate it with thefilm through the above adhesive layer to improve adhesion to thebiaxially oriented film.

[0166] It is desired that the second adhesive layer should havere-releasability, should leave no paste after it is removed and shouldnot peel off or form air bubbles in a forced aging test at a hightemperature and a high humidity. The second adhesive having the aboveproperties is suitably selected from acrylic, rubber-based, polyvinylether-based and silicone-based adhesives. Acrylic adhesives are the mostpreferred. The acrylic adhesives are obtained by copolymerizing an alkyl(meth)acrylic acid ester with a polymerizable unsaturated carboxylicacid or hydroxyl group-containing ethylenically unsaturated monomer andfurther a copolymerizable vinyl-based monomer in an organic solvent orwater medium. Polymerization is preferably radical polymerization.Solution polymerization, suspension polymerization or emulsionpolymerization is preferably used.

[0167] The number average molecular weight measured by gel permeationchromatography of the above copolymer is 9,500 to 950,000, preferably50,000 to 500,000, more preferably 95,000 to 400,000. When the numberaverage molecular weight is lower than 9,500, it is difficult to form auniform resin composition layer and when the number average molecularweight is higher than 950,000, the elasticity becomes high and it isdifficult to adjust the coating weight.

[0168] The above alkyl (meth)acrylic acid ester is preferably methyl(meth)acrylate, butyl (meth)acrylate or octyl (meth) acrylate having analkyl group with 1 to 12 carbon atoms. Specific examples of the alkylmethacrylate include methyl methacrylate, ethyl methacrylate, n-propylmethacrylate, isopropyl methacrylate, n-hexyl methacrylate, cyclohexylmethacrylate, 2-ethylhexyl methacrylate, n-octyl methacrylate, isooctylmethacrylate and lauryl methacrylate. Specific examples of the alkylacrylate include methyl acrylate, ethyl acrylate, propyl acrylate, butylacrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate andlauryl acrylate. They may be used alone or in combination of two ormore.

[0169] The second adhesive may be mixed with a crosslinking agent. Theamount of the crosslinking agent is generally 0.01 to 10 parts by weightbased on 100 parts by weight of the acrylic adhesive. Examples of thecrosslinking agent include isocyanate-based compounds, aluminum chelate,aziridinyl-based compounds and epoxy-based compounds. The secondadhesive is applied to a base film with a coater such as a roll coater,reverse coater, comma coater, lip coater or die coater as an organicsolvent solution. A film or paper which has been subjected to a releasetreatment is laminated with the base film on the adhesive layer side toimprove handling ease.

[0170] The near infrared screening film having the above laminatestructure on the first single-layer film can be directly assembled withthe glass substrate of a plasma display before use. The plasma displaydevice comprising this near infrared screening film has excellentvisibility and abrasion resistance and absorbs near infrared raysradiated from the inside of PDP, thereby causing no trouble in aperipheral remote control unit.

[0171] Preferably, the second single-layer film is assembled with anelectromagnetic shielding thin film laminated film to prevent a problemsuch as the malfunction of peripheral equipment caused by near infraredrays radiated from a plasma display panel and the resulting laminatedfilm is used on the front panel of a plasma display device. Thetransmittances at 850 nm and 950 nm out of the near infrared wavelengthrange of the laminated film must be 0.01 or more and 0.20 or less. Theyare preferably 0.1 or less. When the transmittances for near infraredrays having wavelengths of 850 nm and 950 nm are higher than 0.20, nearinfrared rays radiated from the plasma display panel cannot be shieldedcompletely, whereby the malfunction of plasma display peripheralequipment may occur. When the transmittances are lower than 0.01, thetransmittance for visible rays lowers and the brightness of the plasmadisplay deteriorates according to the characteristic properties of thenear infrared light absorber.

[0172] The above electromagnetic shielding thin film laminated filmpreferably comprises an electromagnetic shielding transparent conducivelayer on at least one side of a transparent base film. This transparentconductive layer is composed of a Sb-doped SnO₂ or Sn-doped In₂O₃ (ITO)semiconductor thin film having a wide optical band gap and a high freeelectron density, or an Au, Ag, Cu or Al film. Out of these, an Ag filmis particularly preferred because it rarely absorbs visible rays. Two ormore metal substances may be used in combination as required. The methodof forming the metal layer is preferably vapor deposition, morepreferably sputtering, vacuum deposition or plasma CVD. The thickness ofthe metal layer must be set to achieve a visible light transmittance of70% or more and a near infrared screening ratio of 40% or more. Thethickness of the metal layer is preferably 5 to 1,000 nm. When thethickness is smaller than 5 nm, the surface resistance becomes high anda satisfactory electromagnetic shielding effect is not obtained and whenthe thickness is larger than 1,000 nm, the visible light transmittancelowers with the result of deteriorated transparency.

[0173] A transparent dielectric layer having a high refractive index ispreferably formed on the above electromagnetic shielding thin filmlaminated film to suppress the reflection of visible rays and improvetransparency. The dielectric is TiO₂, ZrO₂, SnO₂ or In₂O₃. TiO₂ or ZrO₂derived from an organic compound obtained by hydrolyzing an alkyltitanate or alkyl zirconium is preferred because they have excellentworkability. In addition, an indium oxide or tin oxide single-layer ormulti-layer may also be used as the dielectric layer. The method offorming the dielectric layer is preferably vapor-phase deposition, morepreferably sputtering, vacuum deposition or plasma CVD. The above metallayer is preferably sandwiched by the dielectric layers to increase theeffect of transparency. The thickness of the dielectric layer must beset together with that of the above metal layer to achieve the opticalproperties of the structure of the present invention. The thickness ofthe dielectric layer is 0 to 750 nm, preferably 10 to 500 nm.

[0174] The above transparent base film is preferably a biaxiallyoriented polyester film having a thickness of 25 to 250 μm, preferably25 to 175 μm. The polyester for forming this biaxially oriented film maybe identical to the polyester of the biaxially oriented filmconstituting the near infrared screening film. The biaxial orientationheat treatment conditions may be the same as those of the biaxiallyoriented film.

[0175] The laminated film obtained by assembling the second single-layerfilm with the electromagnetic shielding thin film laminated film in thepresent invention may comprise a metal mesh between the secondsingle-layer film and the electromagnetic shielding thin film laminatedfilm to improve electromagnetic shielding properties.

[0176] A description is subsequently given of the laminated film of thepresent invention.

[0177] As for what is not described of the laminated film of the presentinvention, it should be understood that the description of the abovesingle-layer film is applied directly or with modifications obvious toone of ordinary skill in the art.

[0178] The laminated film of the present invention comprises a biaxiallyoriented film made from a polyester which contains a near infrared lightabsorber having a weight reduction start temperature of at least 280° C.and an electromagnetic shielding film formed on at least one side of thebiaxially oriented film.

[0179] The near infrared light absorber having a weight reduction starttemperature of at least 280° C. and the biaxially oriented film madefrom the polyester containing the above absorber are as described abovein the section of single-layer film, and the electromagnetic shieldingfilm formed on at least one side of the biaxially oriented film is asdescribed above in the section of the second single-layer film.

[0180] Preferably, the above biaxially oriented film of the laminatedfilm has a haze value of 5% or less and optical properties at visibleand near infrared ranges which satisfy the following expressions (5),(6), (7) and (8):

5≦T(850)≦57  (7)

20≦T(950)  (8)

0.7≦T(620)/T(540)≦1.3  (5)

0.7≦T(450)/T(540)≦1.3  (6)

[0181] wherein T(450), T(540), T(620), T(850) and T(950) are as definedhereinabove.

[0182] The optical properties at visible and near infrared ranges of theabove biaxially oriented film preferably satisfy the followingexpressions (7)-1 and (8)-1:

10≦T(850)≦28  (7)-1

20≦T(950)≦55  (8)-1

[0183] wherein T(850) and T(950) are as defined hereinabove.

[0184] The total transmittance for visible rays having a wavelength of400 to 650 nm of the above biaxially oriented film is particularlypreferably 60% or more.

[0185] The above laminated film of the present invention has a hazevalue of 5% or less, a total transmittance for visible rays having awavelength of 400 to 650 nm of 40% or more and optical properties atvisible and near infrared ranges which satisfy the following expressions(5), (6), (7) and (8):

5≦T(850)≦5  (7)

20≦T(950)  (8)

0.7≦T(620)/T(540)≦1.3  (5)

0.7<T(450)/T(540)≦1.3  (6)

[0186] wherein T(450), T(540), T(620), T(850) and T(950) are as definedhereinabove.

[0187] The electromagnetic shielding film of the laminated film of thepresent invention is the same as that described for the secondsingle-layer film. It is particularly preferably formed of thetransparent base film and an electromagnetic shielding transparentconductive film formed on at least one side thereof.

[0188] The laminated film of the present invention is advantageouslyused as a film consisting of the laminated film and an adhesive layerformed on at least one side of the laminated film, a film consisting ofthe laminated film, an adhesive layer formed on both sides of thelaminated film, a hard coat layer formed on one of the adhesive layersand a second adhesive layer formed on the other adhesive layer, andpreferably as a film which further comprises an antireflection layerlaminate consisting of at least two thin layers having differentrefractive indices on the surface of the hard coat layer, like the abovesingle-layer film.

EXAMPLES

[0189] The following examples are given to further illustrate thepresent invention. Characteristic property values in examples wereevaluated by the following methods.

[0190] (1) Total Light Transmittance and Haze Value

[0191] The total light transmittance Tt (%) and the scattered lighttransmittance Td (%) were measured with the haze measuring instrument(NDH-20) of Nippon Denshoku Kogyosha Co., Ltd. in accordance with JISK6714-1958.

[0192] The obtained total light transmittance was evaluated based on thefollowing criteria. Level 2 or more means that the total lighttransmittance has no problem with practical use and level 3 means thatthe total light transmittance is extremely excellent.

[0193] 3: total light transmittance of 60% or more

[0194] 2: total light transmittance of 40% or more and less than 60%

[0195] 1: total light transmittance of less than 40%

[0196] The haze (%) was calculated from the measured total lighttransmittance Tt(%) and scattered light transmittance Td (%) accordingto the following expression.

Haze (%)=(Td/Tt)×100

[0197] The obtained haze value was evaluated based on the followingcriteria.

[0198] 4: haze value≦2.0%; haze value is very small and the film can beused practically extremely well

[0199] 3: 2.0%<haze value≦3.0%; haze value is small and the film can beused practically well

[0200] 2: 3.0%<haze value≦5.0%; haze value is a little small and thereis no problem with practical use

[0201] 1: 5.0%<haze value; haze value is large and there is a problemwith practical use

[0202] (2) Light Transmittance at a Wavelength of 400 to 1,500 nm andOptical Density

[0203] The transmittance at a wavelength of 400 to 1,500 nm was measuredwith the MPC3100 spectrophotometer of Shimadzu Corporation.

[0204] (3) Difference in Hue

[0205] L*, a* and b* in an L*a*b* display system were obtained from thetransmission spectrum for standard light A of a sample film inaccordance with JIS standard Z8729 and ab chroma (C*ab) was calculatedfrom the following expression. The difference between chroma and achromawas evaluated from the obtained C*ab based on the following criteria.

[0206] ⊚: C*ab is less than 10

[0207] ◯: C*ab is 10 or more and less than 20

[0208] X: C*ab is 20 or less

[0209] C*ab=((a*)²+(b*)²)^(1/2)

[0210] (4) Evaluation of Color Nonuniformity

[0211] The transmittance at 550 nm was measured at 20 sites selected atrandom from 1 m² of a-sample with the MPC3100 spectrophotometer ofShimadzu Corporation. A value (R: %) obtained by dividing the differencebetween the maximum value and the minimum value of transmittance by theaverage value was calculated to be evaluated as follows.

[0212] ◯: R (%) is 5% or less; absolutely no problem with use of PDP andnot judged as color nonuniformity

[0213] Δ: R (%) is more than 5% and 10% or less; judged as colornonuniformity when observed closely

[0214] X: R (%) is more than 10%; can be recognized as colornonuniformity at the time of using PDP and a single-color image lookspartly tinted with another color

[0215] (5) Abrasion Resistance of Near Infrared Screening Film

[0216] The abrasion resistance of the sample was evaluated from thedifference in haze value (Δ haze) before and after an abrasion test(load of 1 kg, 50 round trips) made by a reciprocating abrasion testerby mounting steel wool #000 on a square pad (area of 6.25 cm²) asfollows.

[0217] Δhaze=(haze value after abrasion test)−(haze value beforeabrasion test)

[0218] ◯: A haze is less than 10

[0219] Δ: A haze is 10 or more and less than 20

[0220] X: A haze is 20 or more

[0221] (6) Adhesive Force

[0222] a. To Adhesive

[0223] The sample was kept in a thermo-hygrostat maintained at 60° C.and 80%RH for 24 hours, the pressure sensitive adhesive layer of thesample was assembled with a glass plate, and the adhesive force of thesample was evaluated by a stripping test based on the followingcriteria.

[0224] ⊚: adhesive force is so high that the base film is broken

[0225] : the sample peels off but has practical utility value

[0226] X: the sample easily peels off and has no practical utility value

[0227] b. To Hard Coat

[0228] Cross cuts were made into the hard coat layer of the samplehaving no antireflection layer to form 100 squares (size: 1 mm×1 mm) anda 24 mm wide cellophane tape was affixed to the layer and stripped offquickly at a peel angle of 180°. The surface of the hard coat layer fromwhich the tape was stripped off was observed to evaluate the adhesiveforce based on the following criteria.

[0229] 5: total removed area is less than 10%; extremely high adhesiveforce

[0230] 4: total removed area is 10% or more and less than 20%; highadhesive force

[0231] 3: total removed area is 20% or more and less than 30%; moderateadhesive force

[0232] 2: total removed area is 30% or more and less than 40%; lowadhesive force

[0233] 1: total removed area is more than 40%; extremely low adhesiveforce

[0234] (7) Near Infrared Screening Ability

[0235] The obtained multi-layer film was placed on the light receivingsection of a remote control unit for a home TV and remote controlsignals (signal wavelengths of 950 nm and 850 nm) were sent by theremote control unit from 2 m away from the TV to test if the home TVresponds to the signals.

[0236] Since near infrared rays from the PDP display are weaker thannear infrared rays from the remote control unit, if no response isobserved in this test, the prevention of an interference with the remotecontrol unit is possible.

[0237] When the TV does not respond to the remote control unit, nearinfrared screening ability is evaluated as ◯ and when the TV responds tothe remote control unit, near infrared screening ability is evaluated asX.

Example 1

[0238] Molten polyethylene terephthalate (PET, [η]=0.65) containing 0.05wt % of the EX814K near infrared light absorber of Nippon Shokubai Co.,Ltd., 0.05 wt % of the EX812K near infrared light absorber of NipponShokubai Co., Ltd. and 0.007 wt % of porous silica having an averageparticle diameter of 1.7 μm was extruded from a die and cooled on acooling drum by a commonly used method to obtain an unstretched film.This unstretched film was stretched to 3.5 times in a longitudinaldirection at 90° C. Thereafter, an aqueous solution containing 8% of thefollowing coating composition was uniformly applied to both sides of thestretched film with a roll coater, and then the resulting laminate wasstretched to 3.8 times in a transverse direction at 120° C. while it wasdried at 95° C. and heat set at 230° C. to obtain a near infraredscreening film having a thickness of 188 μm. The thickness of theadhesive layer was 0.15 μm. The evaluation results of the obtained filmare shown in Table 1. Coating composition Copolyester having a Tg of 68°C. 80 wt % synthesized from terephthalic acid (90 mol %), isophthalicacid (6 mol %) and potassium 5-sulfoisophthalate (4 mol %) as acidcomponents and ethylene glycol (95 mol %) and neopentyl glycol (5 mol %)as glycol components N,N′-ethylenebiscaprylic acid amide  5 wt % Acrylicresin fine particle (average particle 10 wt % diameter of 0.03 μm)Polyoxyethylene nonylphenyl ether  5 wt %

Examples 2 and 3

[0239] The procedure of Example 1 was repeated except that the nearinfrared light absorber was changed as shown in Table 1. The evaluationresults of the obtained films are shown in Table 1. The transmittance ofthe film used in Example 2 is shown in FIG. 1.

Example 4

[0240] Molten polyethylene-2,6-naphthalene dicarboxylate (PEN, [η]=0.65)containing 0.05 wt % of the EX814K near infrared light absorber ofNippon Shokubai Co., Ltd., 0.05 wt % of the EX812K near infrared lightabsorber of Nippon Shokubai Co., Ltd. and 0.007 wt % of porous silicahaving an average particle diameter of 1.7 μm was extruded from a dieand cooled on a cooling drum by a commonly used method to obtain anunstretched film. This unstretched film was stretched to 3.5 times in alongitudinal direction at 130° C. Thereafter, an aqueous solutioncontaining 8% of the following coating composition was uniformly appliedto both sides of the stretched film with a roll coater, and then theresulting laminate was stretched to 3.8 times in a transverse directionat 120° C. while it was dried at 145° C. and heat set at 230° C. toobtain a near infrared screening film having a thickness of 188 μm. Thethickness of the adhesive coating film was 0.15 μm. The evaluationresults of the obtained film are shown in Table 1. Coating compositionCopolyester having a Tg of 68° C. synthesized from terephthalic 80 wt %acid (90 mol %), isophthalic acid (6 mol %) and potassium5-sulfoisophthalate (4 mol %) as acid components and ethylene glycol (95mol %) and neopentyl glycol (5 mol %) as glycol componentsN,N′-ethylenebiscaprylic acid amide  5 wt % Acrylic resin fine particle(average particle diameter of 10 wt % 0.03 μm) Polyoxyethylenenonylphenyl ether  5 wt %

Comparative Example 1

[0241] The procedure of Example 1 was repeated except that no nearinfrared light absorber was used. The evaluation results of the obtainedfilm are shown in Table 1. The film had no near infrared lightabsorptivity.

Comparative Examples 2 and 3

[0242] The procedure of Example 1 was repeated except that the nearinfrared light absorber was changed as shown in Table 1. The evaluationresults of the obtained films are shown in Table 1. Comparative Example2 had no problem with near infrared light absorptivity but had a lowtotal light transmittance. TABLE 1 amount of T T absorber 1 absorber 2absorber (850) (900) polyester (wt %) (wt %) (g/m²) (%) (%) Ex. 1 PET A(0.05) B (0.05) 0.03 33 40 Ex. 2 PET C (0.08) — 0.024 12 14 Ex. 3 PET A(0.05) — 0.015 47 82 Ex. 4 PEN C (0.05) — 0.015 38 40 C. Ex. 1 PET NoneNone 0 0 90 C. Ex. 2 PET A (0.4) B (0.4) 0.24 2.7 0.1 C. Ex. 3 PET A(0.01) B (0.01) 0.006 61 62 near infrared screening T (950) total lightdifference ability (%) transmittance haze in hue 850 950 Ex. 1 72 3 4 ⊚X X Ex. 2 40 3 4 ◯ ◯ X Ex. 3 89 3 4 ◯ X X Ex. 4 61 3 4 ⊚ X X C. Ex. 1 903 4 ⊚ X X C. Ex. 2 0.3 1 3 X ◯ ◯ C. Ex. 3 67 3 4 ⊚ X X

[0243] Letters in Table 1 signify the following (the same shall apply toTable 2).

[0244] A: EX814K near infrared light absorber of Nippon Shokubai Co.,Ltd.

[0245] B: EX812K near infrared light absorber of Nippon Shokubai Co.,Ltd.

[0246] C: IR-ADDITIVE200 near infrared light absorber of Dainippon andInk Chemicals, Inc.

[0247] D: KAYASORB IRG-023 of Nippon Kayaku Co., Ltd.

Example 5

[0248] A UV curable composition having the following composition wasuniformly applied to the adhesive coating film formed on one side of thenear infrared screening film of Example 1 with a roll coater to ensurethat the thickness of the cured film became 5 μm. UV curable compositionPentaerythritol acrylate 45 wt % N-methylolacrylamide 40 wt % N-vinylpyrrolidone 10 wt % 1-hydroxycyclohexylphenyl ketone  5 wt %

[0249] Thereafter, the obtained coating film was cured by exposure toultraviolet radiation from a high-pressure mercury lamp having anintensity of 80 W/cm for 30 seconds to form a hard coat layer.

[0250] Then, an antireflection layer laminate consisting of a lowrefractive index layer (SiO₂, 30 nm), a high refractive index layer(TiO₂, 30 nm), a low refractive index layer (SiO₂, 30 nm), a highrefractive index layer (TiO₂, 100 nm) and a low refractive index layer(SiO₂, 100 nm) formed in the mentioned order was formed on the hard coatlayer by sputtering. Subsequently, an adhesive coating solution a(adhesive content of 20 wt %) prepared by the following method wasuniformly stirred and applied to a 38 μm-thick PET film subjected to arelease treatment so as to ensure that the thickness of the driedadhesive layer became 25 μm, and dried. The resulting laminate wasassembled with a 188 μm-thick transparent PET film subjected to theabove antireflection treatment in such a manner that the adhesive layerwas placed on the untreated side of the PET film to obtain the nearinfrared screening film (laminated film) of the present invention.

[0251] The thus obtained laminated film was assembled with anelectromagnetic shielding thin film laminated film coated with anadhesive on one side (manufactured by Teijin Shoji Co., Ltd., tradename: Reftel XIR-70). The optical properties of the obtained laminateand the evaluation results of the obtained display device are shown inTable 2.

[0252] Preparation of Adhesive Coating Solution a

[0253] A solution having the following composition was prepared in aflask equipped with a thermometer, stirrer, reduction cooling tube andnitrogen feed pipe. Composition of acrylic solution n-butyl acrylate47.0 wt % acrylic acid  3.0 wt % benzoyl peroxide  0.2 wt % ethylacetate 20.0 wt % toluene 29.8 wt %

[0254] After nitrogen was introduced from the nitrogen feed pipe tocreate a nitrogen atmosphere in the flask, a polymerization reaction wascarried out by heating at 65° C. for 10 hours to obtain an acrylicpolymer solution having a weight average molecular weight of about1,200,000 (number average molecular weight of about 300,000) and a Tg ofabout −49° C. Ethyl acetate was added to this acrylic polymer solutionto ensure that the solid content of this acrylic polymer solution became20 wt % so as to obtain an acrylic polymer solution for a master batch.0.1 part by weight of N,N,N′,N′-tetraglycidyl-m-xylenediamine was addedto 100 parts (solid content) by weight of this solution to obtain theadhesive coating solution a.

[0255] Examples 6 to 8

[0256] The procedure of Example 5 was repeated except that the filmsused in Examples 2 to 4 were used. The evaluation results of theobtained laminated films are shown in Table 2. The transmittance of thelaminated film used in Example 6 (before it was assembled with anelectromagnetic shielding thin film laminated film) is shown in FIG. 2.

Comparative Example 4

[0257] The procedure of Example 5 was repeated except that the filmobtained in Example 1 was changed to the film obtained in ComparativeExample 1. The evaluation results of the obtained laminated film areshown in Table 2. The obtained film did not show satisfactory nearinfrared screening ability at a wavelength of 850 nm.

Comparative Example 5

[0258] The procedure of Example 5 was repeated except that the filmobtained in Example 1 was changed to the film obtained in ComparativeExample 3. The evaluation results of the obtained laminated film areshown in Table 2. The obtained film did not show satisfactory nearinfrared screening ability at a wavelength of 850 nm.

Comparative Example 6

[0259] A UV curable composition having the following composition wasuniformly applied to the coating film formed on one side of thepolyester film of Comparative Example 1 with a roll coater to ensurethat the thickness of the cured film became 5 μm. UV curable compositionPentaerythritol acrylate 45 wt % N-methylolacrylamide 40 wt %N-vinylpyrrolidone 10 wt % 1-hydroxycyclohexylphenyl ketone  5 wt %

[0260] Thereafter, the obtained coating film was cured by exposure toultraviolet radiation from a high-pressure mercury lamp having anintensity of 80 W/cm for 30 seconds to form a hard coat layer.

[0261] Then, an antireflection layer laminate consisting of a lowrefractive index layer (SiO₂, 30 nm), a high refractive index layer(TiO₂, 30 nm), a low refractive index layer (SiO₂, 30 nm), a highrefractive index layer (TiO₂, 100 nm) and a low refractive index layer(SiO₂, 100 nm) formed in the mentioned order was formed on the abovehard coat layer by sputtering. Subsequently, an adhesive coatingsolution a (adhesive content of 20 wt %) prepared by the followingmethod was uniformly stirred and applied to a 38 μm-thick PET filmsubjected to a release treatment to ensure that the thickness of thedried adhesive layer became 25 μm and dried. The resulting laminate wasassembled with a 188 μm-thick transparent PET film subjected to theabove antireflection treatment in such a manner that the adhesive layerwas placed on the untreated side of the PET film to obtain a laminatedfilm. The evaluation results of the thus obtained laminated film anddisplay device are shown in Table 2. Although the laminated film showedsatisfactory near infrared screening ability, the amount of the nearinfrared light absorber was large, thus boosting cost and adhesionbetween the adhesive layer and the film was poor.

[0262] Preparation of Adhesive Coating Solution b

[0263] A solution having the following composition was prepared in aflask equipped with a thermometer, stirrer, reduction cooling tube andnitrogen feed pipe. Composition of acrylic solution n-butyl acrylate47.0 wt % acrylic acid  3.0 wt % benzoyl peroxide  0.2 wt % ethylacetate 20.0 wt % toluene 29.6 wt % IR-Additive200 near infrared lightabsorber of  0.4 wt % Dainippon and Ink Chemicals, Inc.

[0264] After nitrogen was introduced from the nitrogen feed pipe tocreate a nitrogen atmosphere in the flask, a polymerization reaction wascarried out by heating at 65° C. for 10 hours to obtain an acrylicpolymer solution having a weight average molecular weight of about1,200,000 (number average molecular weight of about 300,000) and a Tg ofabout −49° C. Ethyl acetate was added to this acrylic polymer solutionto ensure that the solid content of this acrylic polymer solution became20 wt % so as to obtain an acrylic polymer solution for a master batch.0.1 part by weight of N,N,N′,N′-tetraglycidyl-m-xylylenediamine wasadded to 100 parts (solid content) by weight of this solution to obtainthe adhesive coating solution b.

Comparative Example 7

[0265] The procedure of Comparative Example 2 was repeated except thatthe near infrared light absorber to be added to the adhesive coatingsolution b was changed as shown in Table 2 and the thickness of theadhesive layer was changed to 45 μm. The evaluation results of theobtained laminated film are shown in Table 2. Although the laminatedfilm showed satisfactory near infrared screening ability, the amount ofthe near infrared light absorber was large, thus boosting cost andadhesion between the adhesive layer and the transparent base film waspoor. TABLE 2 antistatic near infrared light metal film adhesive layeramount of transmittance of laminate base multi-layer thickness ofabsorber 1 absorber 2 absorber T800 T900 T950 film laminate adhesive(μm) (wt %) (wt %) (g/m²) (%) (%) (%) Ex. 5 Ex. 1 Existent 25 — —(0.030) 13 11 12 Ex. 6 Ex. 2 Existent 25 — — (0.024) 9 7 9 Ex. 7 Ex. 3Existent 25 — — (0.015) 17 22 18 Ex. 8 Ex. 4 Existent 25 — — (0.015) 1211 12 C. Ex. 4 C. Ex. 1 Existent 25 — — 0.000 35 25 18 C. Ex. 5 C. Ex. 3Existent 25 — — (0.006) 29 22 14 C. Ex. 6 C. Ex. 1 Non-existent 45 C(0.4) — 0.029 12 14 40 C. Ex. 7 C. Ex. 1 Non-existent 45 A (0.4) D (0.4)0.058 11 13 18 near infrared adhesive force screening ability totallight difference surface abrasion to adhesive to hard coat 850 950 hazetransmittance in hue reflection resistance Ex. 5 ⊚ 5 ◯ ◯ 4 4 ◯ ⊚excellent Ex. 6 ⊚ 5 ◯ ◯ 4 3 ⊚ ⊚ excellent Ex. 7 ⊚ 5 ◯ ◯ 4 3 ⊚ ⊚excellent Ex. 8 ⊚ 5 ◯ ◯ 4 4 ◯ ⊚ excellent C. Ex. 4 ◯ 5 X ◯ 4 3 ⊚ ⊚excellent C. Ex. 5 X 5 X ◯ 3 2 ◯ ⊚ excellent C. Ex. 6 X 5 ◯ X 4 2 X ⊚excellent C. Ex. 7 X 5 ◯ ◯ 4 2 ◯ ⊚ excellent

Example 9

[0266] Molten polyethylene terephthalate (PET, [η]=0.65) containing 0.40wt % of the EX814K near infrared light absorber of Nippon Shokubai Co.,Ltd., 0.20 wt % of the S13 near infrared light absorber of MitsuiChemical, Inc. and 0.007 wt % of porous silica having an averageparticle diameter of 1.7 μm was extruded from a die and cooled on acooling drum by a commonly used method to obtain an unstretched filmwhich was then stretched to 3.5 times in a longitudinal direction at 90°C. Thereafter, an aqueous solution containing 8% of the followingcoating composition was uniformly applied to both sides of the stretchedfilm with a roll coater, and then the resulting laminate was stretchedto 3.8 times in a transverse direction at 120° C. while it was dried at95° C. and heat set at 230° C. to obtain a near infrared screeningbiaxially oriented film having a thickness of 75 μm. The thickness ofthe adhesive layer was 0.15 μm. The evaluation results of the obtainedfilm are shown in Table 3. The transmittance of the film is shown inFIG. 3. Coating composition Copolyester resin having a Tg of 68° C.synthesized from 80 wt % terephthalic acid (90 mol %), isophthalic acid(6 mol %) and potassium 5-sulfoisophthalate (4 mol %) as acid componentsand ethylene glycol (95 mol %) and neopentyl glycol (5 mol %) as glycolcomponents N,N′-ethylenebiscaprylic acid amide  5 wt % Acrylic resinfine particle (average particle diameter of 0.03 μm) 10 wt %Polyoxyethylene nonylphenyl ether  5 wt %

Examples 10 to 13

[0267] The procedure of Example 9 was repeated except that the nearinfrared light absorber was changed as shown in Table 3. The evaluationresults of the obtained near infrared screening films are shown in Table3. The transmittance of the film obtained in Example 11 is shown in FIG.4.

Example 14

[0268] Molten polyethylene-2,6-naphthalene dicarboxylate (PEN, [η]=0.65)containing 0.40 wt % of the EX814K near infrared light absorber ofNippon Shokubai Co., Ltd., 0.20 wt % of the S13 near infrared lightabsorber of Mitsui Chemical, Inc. and 0.007 wt % of porous silica havingan average particle diameter of 1.7 ηm was extruded from a die andcooled on a cooling drum by a commonly used method to obtain anunstretched film which was then stretched to 3.5 times in a longitudinaldirection at 130° C. Thereafter, an aqueous solution containing 8% ofthe following coating composition was uniformly applied to both sides ofthe stretched film with a roll coater, and then the resulting laminatewas stretched to 3.8 times in a transverse direction at 120° C. while itwas dried at 145° C. and heat set at 230° C. to obtain a near infraredscreening film having a thickness of 75 μm. The thickness of theadhesive layer was 0.15 μm. The evaluation results of the obtained filmare shown in Table 3. Coating composition Copolyester resin having a Tgof 68° C. synthesized from 80 wt % terephthalic acid (90 mol %),isophthalic acid (6 mol %) and potassium 5-sulfoisophthalate (4 mol %)as acid components and ethylene glycol (95 mol %) and neopentyl glycol(5 mol %) as glycol components N,N′-ethylenebiscaprylic acid ainide  5wt % Acrylic resin fine particle (average particle diameter of 0.03 μm)10 wt % Polyoxyethylene nonylphenyl ether  5 wt %

Comparative Example 8

[0269] The procedure of Example 9 was repeated except that no nearinfrared light absorber was used. The evaluation results of the obtainedbiaxially oriented film are shown in Table 3. The obtained film had nonear infrared absorptivity.

Comparative Examples 9 to 12

[0270] The procedure of Example 9 was repeated except that the nearinfrared light absorber was changed as shown in Table 3. The evaluationresults of the obtained near infrared screening films are shown in Table3. The film of Comparative Example 9 had no problem with near infraredabsorptivity but a low total light transmittance. The film ofComparative Example 10 had unsatisfactory near infrared absorptivity.TABLE 3 near infrared light absorber amount of near weight reductioninfrared light T(850) polyester type (weight) start temperature absorber(g/m²) T (450) − T(620) T(450) − T(540) (%) Ex. 9 PET E 0.60% >300° C.0.70 −0.6 −9.0 11.2 Ex. 10 PET F 0.47% >300° C. 0.56 −0.7 −6.6 5.6 Ex.11 PET G 0.67% 282° C. 0.80 −1.1 1.5 12.7 Ex. 12 PEN H 0.47% >300° C.0.56 −3.4 −6.2 12.4 Ex. 13 PET I 0.40% 280° C. 0.48 −0.9 −8.8 12.7 Ex.14 PEN E 0.60% >300° C. 0.72 −0.6 −9.0 11.2 C. Ex. 8 PET None 0.00% —0.00 0.2 −0.7 91.0 C. Ex. 9 PET J 0.33% 230° C. 0.40 1.0 3.3 18.4 C. Ex.10 PET K 0.35% >300° C. 0.42 0.6 1.1 32.3 C. Ex. 11 PET L 1.00% 280° C.1.20 −4.5 −12.5 0.4 C. Ex. 12 PET M 0.40% 220° C. 0.48 −1.3 −4.5 6.3color heat near infrared total light resistance upon screening T(900)T(950) transmittance haze difference color recovery of raw ability (%)(%) (%) (%) in hue nonuniformity materials 850 950 Ex. 9 4.2 7.8 52 4 ◯◯ ⊚ ◯ ◯ Ex. 10 3.1 10.1 61 4 ◯ ◯ ⊚ ◯ ◯ Ex. 11 17.4 18.7 51 4 ⊚ ◯ ◯ ◯ ◯Ex. 12 11.0 14.9 52 4 ◯ ◯ ◯ ◯ ◯ Ex. 13 17.4 18.7 51 4 ◯ ◯ ◯ ◯ ◯ Ex. 144.2 7.8 52 4 ◯ ◯ ⊚ ◯ ◯ C. Ex. 8 91.0 91.0 90 4 ⊚ — — X X C. Ex. 9 68.685.0 72 4 ⊚ ◯ ⊚ ◯ X C. Ex. 10 35.3 43.2 73 4 ⊚ ◯ X X X C. Ex. 11 1.011.9 34 3 X ◯ X ◯ ◯ C. Ex. 12 4.2 4.1 34 3 X ◯ X ◯ ◯

[0271] Letters E to M in Table 3 represent the types and amounts of thefollowing near infrared light absorbers (wt % after mixed with apolyester).

[0272] E: EX814K near infrared light absorber of Nippon Shokubai Co.,Ltd. (0.40 wt %) and S13 near infrared light absorber of MitsuiChemical, Inc. (0.20 wt %)

[0273] F: EX812K near infrared light absorber of Nippon Shokubai Co.,Ltd. (0.07 wt %), EX814K (0.27 wt %) and S13 near infrared lightabsorber of Mitsui Chemical, Co., Ltd. (0.27 wt %)

[0274] G: EX812K near infrared light absorber of Nippon Shokubai Co.,Ltd. (0.13 wt %) EX814K (0.27 wt %) and EX906B near infrared lightabsorber of Nippon Shokubai Co., Ltd. (0.27 wt %)

[0275] H: EX906B near infrared light absorber of Nippon Shokubai Co.,Ltd. (0.27 wt %) and R12 near infrared light absorber of MitsuiChemical, Inc. (0.20 wt %)

[0276] I: EX814K near infrared light absorber of Nippon Shokubai Co.,Ltd. (0.20 wt %) and S13 near infrared light absorber of MitsuiChemical, Inc. (0.13 wt %)

[0277] J: EX814K near infrared light absorber of Nippon Shokubai Co.,Ltd. (0.33 wt %)

[0278] K: IRG-023 near infrared light absorber of Nippon Kayaku Co.,Ltd. (0.15 wt %) and EX814K near infrared light absorber of NipponShokubai Co., Ltd. (0.20 wt %)

[0279] L: IR-ADDITIVE200 near infrared light absorber of Dainippon andInk Chemicals, Inc. (1.00 wt %)

[0280] M: SDO-1000B near infrared light absorber of Arimoto Kagaku Co.,Ltd. (0.20 wt %) and IR-ADDITIVE200 near infrared light absorber ofDainippon and Ink Chemicals, Inc. (0.20 wt %)

Example 15

[0281] The same UV curable composition as in Example 5 was uniformlyapplied to one side of the near infrared screening film obtained inExample 9 with a roller coater to ensure that the thickness of the curedcoating film became 5 μm.

[0282] Thereafter, the obtained coating film was cured by exposure toultraviolet radiation from a high-pressure mercury lamp having anintensity of 80 W/cm for 30 seconds to form a hard coat layer.

[0283] An antireflection layer laminate consisting of a low refractiveindex layer (SiO₂, 30 nm), a high refractive index layer (TiO₂, 30 nm),a low refractive index layer (SiO₂, 30 nm), a high refractive indexlayer (TiO₂, 100 nm) and a low refractive index layer (SiO₂, 100 nm)formed in the mentioned order was formed on the above hard coat layer bysputtering.

[0284] Subsequently, an adhesive coating solution c (adhesive content of20 wt %) prepared by the following method was uniformly stirred andapplied to a 38 μm-thick polyethylene terephthalate (PET) film subjectedto a release treatment to ensure that the thickness of the driedadhesive layer became 25 μm and dried. The resulting laminate wasassembled with a 75 μm-thick near infrared screening film subjected tothe above antireflection treatment in such a manner that the adhesivelayer was placed on the untreated side of the film to obtain the nearinfrared screening laminated film of the present invention. Theevaluation results of the thus obtained laminated film and displaydevice are shown in Table 4.

[0285] Preparation of Adhesive Coating Solution c

[0286] A solution having the following composition was prepared in aflask equipped with a thermometer, stirrer, reduction cooling tube andnitrogen feed pipe. Composition of acrylic solution n-butyl acrylate47.0 wt % acrylic acid  3.0 wt % benzoyl peroxide  0.2 wt % ethylacetate 20.0 wt % toluene 29.8 wt % EX814K near infrared light absorberof Nippon Shokubai  0.1 wt % Co., Ltd. EX907B near infrared lightabsorber of Nippon Shokubai  0.1 wt % Co., Ltd.

[0287] After nitrogen was introduced from the nitrogen feed pipe tocreate a nitrogen atmosphere in the flask, a polymerization reaction wascarried out by heating at 65° C. for 10 hours to obtain an acrylicpolymer solution having a weight average molecular weight of about1,200,000 (number average molecular weight of about 300,000) and a Tg ofabout −49° C. Ethyl acetate was added to this acrylic polymer solutionto ensure that the solid content of this acrylic polymer solution became20 wt % so as to obtain an acrylic polymer solution for a master batch.0.1 part by weight of N,N,N′,N′-tetraglycidyl-m-xylylenediamine wasadded to 100 parts (solid content) by weight of this solution to obtainthe adhesive coating solution c.

Examples 16 to 20

[0288] The procedure of Example 15 was repeated except that the nearinfrared screening films obtained in Examples 10 to 14 were used. Theevaluation results of the obtained laminated films are shown in Table 4.

Comparative Example 13

[0289] The same UV curable composition as in Comparative Example 6 wasuniformly applied to the coating film on one side of the biaxiallyoriented polyester film of Comparative Example 8 with a roller coater toensure that the thickness of the cured coating film became 5 μm.

[0290] Thereafter, the obtained coating film was cured by exposure toultraviolet radiation from a high-pressure mercury lamp having anintensity of 80 W/cm for 30 seconds to form a hard coat layer.

[0291] An antireflection layer laminate consisting of a low refractiveindex layer (SiO₂, 30 nm), a high refractive index layer (TiO₂, 30 nm),a low refractive index layer (SiO₂, 30 nm), a high refractive indexlayer (TiO₂, 100 nm) and a low refractive index layer (SiO₂, 100 nm)formed in the mentioned order was formed on the above hard coat layer bysputtering. Subsequently, an adhesive coating solution d (adhesivecontent of 20 wt %) prepared by the following method was uniformlystirred and applied to a 38 μm-thick PET film subjected to a releasetreatment to ensure that the thickness of the dried adhesive layerbecame 25 μm and dried. The resulting laminate was assembled with a 75μm-thick near infrared screening film subjected to the aboveantireflection treatment in such a manner that the adhesive layer wasplaced on the untreated side of the film to obtain a near infraredscreening laminated film. The evaluation results of the thus obtainedlaminated film and display device are shown in Table 4. This laminatedfilm did not show satisfactory near infrared screening ability.

[0292] Preparation of Adhesive Coating Solution d

[0293] A solution having the following composition was prepared in aflask equipped with a thermometer, stirrer, reduction cooling tube andnitrogen feed pipe. Composition of acrylic solution n-butyl acrylate47.0 wt % acrylic acid  3.0 wt % benzoyl peroxide  0.2 wt % ethylacetate 20.0 wt % toluene 29.6 wt % EX814K near infrared light absorberof Nippon Shokubai Co..  0.1 wt % Ltd. EX907B near infrared lightabsorber of Nippon Shokubai Co.,  0.1 wt % Ltd.

[0294] After nitrogen was introduced from the nitrogen feed pipe tocreate a nitrogen atmosphere in the flask, a polymerization reaction wascarried out by heating at 65° C. for 10 hours to obtain an acrylicpolymer solution having a weight average molecular weight of about1,200,000 (number average molecular weight of about 300,000) and a Tg ofabout −49° C. Ethyl acetate was added to this acrylic polymer solutionto ensure that the solid content of this acrylic polymer solution became20 wt % so as to obtain an acrylic polymer solution for a master batch.0.1 part by weight of N,N,N′,N′-tetraglycidyl-m-xylenediamine was addedto 100 parts (solid content) by weight of this solution to obtain theadhesive coating solution d.

Comparative Examples 14 to 16

[0295] The procedure of Comparative Example 9 was repeated except thatthe near infrared light absorber to be added to the adhesive coatingsolution d was changed as shown in Table 4 and the thickness of theadhesive layer was changed to 45 μm. The evaluation results of theobtained near infrared screening laminated films are shown in Table 4.The films had low adhesive force between the adhesive layer and a basefilm. TABLE 4 adhesive layer near infrared layer light absorber basethickness Type and evaluation of color adhesive force film (μm) amount(wt %) (g/m²) nonuniformity to adhesive to hard coat Ex. 15 Ex. 9 25 — —◯ ⊚ 5 Ex. 16 Ex. 10 25 — — ◯ ⊚ 5 Ex. 17 Ex. 11 25 — — ◯ ⊚ 5 Ex. 18 Ex.12 25 — — ◯ ⊚ 5 Ex. 19 Ex. 13 25 — — ◯ ⊚ 5 Ex. 20 Ex. 14 25 — — ◯ ⊚ 5 C.Ex. 13 C. Ex. 8 25 N(1.80) 2.16 X ◯ 5 C. Ex. 14 C. Ex. 9 45 O(0.78) 0.92Δ X 5 C. Ex. 15 C. Ex. 9 45 P(0.88) 1.06 Δ X 5 C. Ex. 16 C. Ex. 9 45Q(0.35) 0.42 Δ X 5 near infrared screening ability haze total lightdifference surface abrasion 850 950 (%) transmittance (%) in huereflection resistance Ex. 15 ◯ ◯ 4 52 ◯ ⊚ ◯ Ex. 16 ◯ ◯ 4 61 ◯ ⊚ ◯ Ex. 17◯ ◯ 4 51 ◯ ⊚ ◯ Ex. 18 ◯ ◯ 4 52 ◯ ⊚ ◯ Ex. 19 ◯ ◯ 4 51 ◯ ⊚ ◯ Ex. 20 ◯ ◯ 452 ◯ ⊚ ◯ C. Ex. 13 ◯ ◯ 4 86 ◯ ⊚ ◯ C. Ex. 14 ◯ ◯ 3 75 ◯ ⊚ ◯ C. Ex. 15 ◯ ◯3 63 ◯ ⊚ ◯ C. Ex. 16 ◯ ◯ 3 50 ◯ ⊚ ◯

[0296] Letters N to Q in Table 4 represent the following.

[0297] N: EX814K near infrared light absorber of Nippon Shokubai Co.,Ltd. (1.20 wt %) and S13 near infrared light absorber of MitsuiChemical, Inc.(0.60 wt %)

[0298] O: EX812K (0.11 wt %) and EX814K (0.44 wt %) near infrared lightabsorbers of Nippon Shokubai Co., Ltd. and S13 near infrared lightabsorber of Mitsui Chemical, Inc.(0.22 wt %)

[0299] P: SDO-1000B near infrared light absorber of Arimoto Kagaku Co.,Ltd. (0.44 wt %) and IR-ADDITIVE200 near infrared light absorber ofDainippon and Ink Chemicals, Inc.(0.44 wt %)

[0300] Q: IRG-023 near infrared light absorber of Nippon Kayaku Co.,Ltd. (0.44 wt %) and EX814K near infrared light absorber of NipponShokubai Co., Ltd.(0.33 wt %)

1. A near infrared screening film which consists of (A) a biaxiallyoriented film made from a polyester containing a near infrared lightabsorber having a weight reduction start temperature of at least 280° C.and which has (B) a haze value of 5% or less, (C) a total transmittancefor visible lights having a wavelength of 400 to 650 nm of 40% or moreand (D) optical properties at visible and near infrared ranges whichsatisfy the following expressions (1) to (4): 1<T(850)<20  (1)1<T(950)<20  (2) −10<T(620)−T(540)<10  (3) −10<T(450)−T(540)<10  (4)wherein t(450), t(540), t(620), t(850) and t(950) are lighttransmittances at wavelengths of 450 nm, 540 nm, 620 nm, 850 nm and 950nm, respectively.
 2. The film of claim 1, wherein the near infraredlight absorber has a weight change rate of 10 wt % or less when it iskept at 280° C. for 30 minutes.
 3. The film of claim 1, wherein the nearinfrared light absorber is contained in an amount of 0.10 to 1.00 g per1 m² of a plane perpendicular to the thickness direction of thebiaxially oriented film.
 4. The film of claim 1, wherein the nearinfrared light absorber is a compound having a phthalocyanine skeletonor a nickel complex compound.
 5. A near infrared screening laminatedfilm which comprises (A′) a biaxially oriented film made from apolyester containing a near infrared light absorber having a weightreduction start temperature of at least 280° C. and an electromagneticshielding film formed on at least one side of the biaxially orientedfilm and which has (B) a haze value of 5% or less, (C) a totaltransmittance for visible lights having a wavelength of 400 to 650 nm of40% or more, and (D′) optical properties at visible and near infraredranges which satisfy the following expressions (1), (2), (5) and (6):1<T(850)<20  (1) 1<T(950)<20  (2) 0.7≦T(620)/T(540)≦1.3  (5)0.7≦T(450)/T(540)≦1.3  (6) wherein T(450), T(540), T(620), T(850) andT(950) are as defined hereinabove.
 6. The laminated film of claim 5,wherein the biaxially oriented film has a haze value of 5% or less andoptical properties at visible and near infrared ranges which satisfy thefollowing expressions (5), (6), (7) and (8): 5≦T(850)≦57  (7)20≦T(950)  (8) 0.7≦T(620)/T(540)≦1.3  (5) 0.7≦T(450)/T(540)≦1.3  (6)wherein T(450), T(540), T(620), T(850) and T(950) are as definedhereinabove.
 7. The laminated film of claim 5, wherein the opticalproperties at visible and near infrared ranges of the biaxially orientedfilm satisfy the following expressions (7)-1 and (8)-1:10≦T(850)≦28  (7)-1 20≦T(950)≦55  (8)-1 wherein T(850) and T(950) are asdefined hereinabove.
 8. The laminated film of claim 5, wherein the totaltransmittance for visible rays having a wavelength of 400 to 650 nm ofthe biaxially oriented film is 60% or more.
 9. The laminated film ofclaim 5, wherein the near infrared light absorber is a compound having aphthalocyanine skeleton or a nickel complex compound.
 10. The laminatedfilm of claim 5, wherein the near infrared light absorber is containedin an amount of 0.05 to 1.0 g per 1 m² of a plane perpendicular to thethickness direction of the biaxially oriented film.
 11. The laminatedfilm of claim 5, wherein the electromagnetic shielding film comprises atransparent base film and an electromagnetic shielding transparentconductive film formed on at least one side of the base film.
 12. A filmcomprising the near infrared screening film of claim 1 and an adhesivelayer formed on at least one side of the film.
 13. A film comprising thenear infrared screening film of claim 1, an adhesive layer formed onboth sides of the film, a hard coat layer formed on one of the adhesivelayers and a second adhesive layer formed on the other adhesive layer.14. The film of claim 13 which further comprises an antireflection layerlaminate consisting of at least two thin layers having differentrefractive indices on the hard coat layer.
 15. A film comprising thenear infrared screening laminated film of claim 5 and an adhesive layerformed on at least one side of the film.
 16. A film comprising the nearinfrared screening laminated film of claim 5, an adhesive layer formedon both sides of the film, a hard coat layer formed on one of theadhesive layers and a second adhesive layer formed on the other adhesivelayer.
 17. The film of claim 16 which further comprises anantireflection layer laminate consisting of at least two thin layershaving different refractive indices on the hard coat layer.
 18. Use ofthe film of claim 1 or 5 for adhering on in the front panel of aluminescent panel display in order to screen near infrared lightsradiated from the display.
 19. A near infrared screening film whichconsists of (A) a biaxially oriented film made from a polyestercontaining a near infrared light absorber having a weight reductionstart temperature of at least 280° C. and which has (B) a haze value of5% or less, (C) a total transmittance for visible lights having awavelength of 400 to 650 nm of 60% or more and (D) optical properties atvisible and near infrared ranges which satisfy the following expressions(5), (6), (7) and (8): 5≦T(850)≦57  (7) 20≦T(950)  (8)0.7≦T(620)/T(540)≦1.3  (5) 0.7≦T(450)/T(540)≦1.3  (6) wherein T(450),T(540), T(620), T(850) and T(950) are as defined hereinabove.